It tells in the Monster Manual how a PC can become a Lycanthrope and what mechanical differences it makes, but as far as I can see it doesn't say anything about what level the character should be at or how it would effect Combat Encounter Calculations.
Some of the abilities a PC would get become redundant at high levels, but would be completely broken at lower levels (most notable its damage immunities). Is there a Rule of Thumb or maybe something written in one of the supplement books that would determine what effects lycanthropy would have at different levels?
Some of the things I've calculated are:
- A PC character can gain access to the Polymorph spell at 7th level. Since a lycanthrope has a limited polymorph as one of its abilities, combining that with the other advantages it gets would indicate that level 7 would be the best level for a Were-PC.
- Monks and Circle of the Moon Druids gain access to their respective "your attacks count as magical for the purposes of overcoming resistances" features, meaning they'll start facing creatures with similar damage immunities to the lycanthrope. Combining that with the other advantages it gets would indicate that Level 7 would be the best level for a Were-PC.
- According to some brief CR calculations (using the DMG), the higher-CR lycanthropes seem like even fights with a 7th- or 8th-level party, while lower CRs look good for a 4th- or 5th-level party. So depending on the lycanthropy, a Were-PC would be fine anyway between 4th and 9th level.
Based off the calculations above, I assume that creating a Were-PC at level 10 or higher is fine (if the player wants it), but below level 5 is too powerful. Between levels 5 and 10, a player's level should match or surpass the CR of the lycanthrope + 5 in order to have it; otherwise, it might be too powerful.
This is all assuming the PC "embraces the curse" and the DM allows the player to use it freely. Assuming the opposite, you could subtract 5 from the character's level when using the calculations above.
As for calculating combat encounters, a PC should be considered 1 level higher than their character level when working out combat encounters - until they become level 11 or higher, in which case treat them like a normal PC.
Does all that make sense? Is it a good system, or is there some fact that I'm missing? Does this adequately answer What level should a Lycanthrope PC be? Would any of this be different if you were creating a character at a different level?